The water used in the production of integrated circuits must be deionized and purified as much as possible in order to avoid contamination of the integrated circuits during processing. Conventional water treatment systems employ a central purifying plant that employs a combination of depth filtration, carbon filtration, reverse osmosis, ultraviolet sterilization, ion exchange, and membrane filtration. The purified water from the central plant is pumped to the several fabrication lines and circulated through standard polishing loops immediately prior to use. These standard loops in the prior art, such as that disclosed in "Ultrapure Water in Semiconductor Manufacturing", by R. Taubenest and H. Ubersax, appearing in Solid State Technology, June, 1980, employ a series of ultraviolet sterilization, ion exchange, and membrane filtration operations, in that order; which kill bacteria, increase the resistivity of the water, and remove particles, respectively. The standard piping material in the prior art is polyvinyl chloride (PVC). This material has the disadvantage that it leaches organic matter and particles into the purified water. The ion exchange apparatus also contaminates the water by the leaching of organic material and particles.
U.S. Pat. No. 4,280,912 teaches the use of a process in which the first and last steps of the process employ resins that have improved ability to remove organic matter. These resins are themselves sources of organic matter.